Coniferous Wood of Agathoxylon from the La Matilde Formation, (Middle Jurassic), Santa Cruz, Argentina

Home , Agathoxylon, Araucaria mirabilis, Baieroxylon, La Matilde Formation

Coniferous wood of Agathoxylon from the La Matilde Formation, (Middle Jurassic), Santa Cruz, Argentina

Adriana C. Kloster,1 and Silvia C. Gnaedinger2

1Área de Paleontología, Centro de Ecología Aplicada del Litoral, Consejo Nacional de Investigaciones Cientíﬁcas y Técnicas (CECOAL-CCT CONICET Nordeste-UNNE). 〈[email protected]〉 2Área de Paleontología, Centro de Ecología Aplicada del Litoral, Consejo Nacional de Investigaciones Cientíﬁcas y Técnicas (CECOAL-CCT CONICET Nordeste-UNNE), Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste (FaCENA-UNNE). Casilla de Correo 291, 3400 Corrientes, Argentina, 〈[email protected]〉

Abstract.—In this contribution, four species of Agathoxylon are described from the La Matilde Formation, Gran Bajo de San Julián and central and south-western sectors of Santa Cruz Province, Argentina. Agathoxylon agathioides (Kräusel and Jain) n. comb., Agathoxylon santalense (Sah and Jain) n. comb., Agathoxylon termieri (Attims) Gnaedinger and Herbst, and the new species Agathoxylon santacruzense n. sp. are described based on a detailed description of the secondary xylem. In this work, it was possible to construct scatter plots to elucidate the anatomical differences between the fossil species described on quantitative anatomical data. Comparisons are made with other Agathoxylon species from Gondwana. These parameters can be used to discriminate genera and species of wood found in the same formation, as well as to establish differences/similarities between other taxa described in other formations. Some localities contain innumerable “in situ” petriﬁed trees, which allowed us to infer that these taxa formed small forests, or local forests, or small forests within a dense forest, which is a habitat coincident with the extant Araucariaceae.

Introduction the province (i.e., forests with in situ petrified trunks and rolled trees). These localities are found in the Estancia El Mineral Sediments of the La Matilde Formation crop out in several areas (Laguna La Guadalosa), Estancia Meseta Chica (Barda Blanca, of Santa Cruz province (Argentina), some localities containing Cerro Conito, northern part), and Estancia La Silvita (Laguna “in situ” silicified trees, with many fallen and fragmented exam- del Carbón) (Figs. 1, 2). ples (De Barrios et. al., 1999). The geological and paleontological Anatomical descriptions of Osmundales macrofossils and leaf characteristics of the La Matilde Formation have already been impressions of the orders Equisetales, Osmundales, Bennettitales, described by several authors (e.g., Delhaes, 1913; Frenguelli, and Coniferales have been made from these outcrops (Feruglio, 1933; Feruglio, 1949; Stipanicic and Reig, 1957; Spalletti et al., 1951; Archangelsky and de la Sota, 1962; Herbst, 1977, 2003; 1982; Panza and Irigoyen, 1995; Panza, 1998). Baldoni, 1981, 1990; Herbst and Salazar, 1999). In addition, also Sediments of the La Matilde Formation crop out in diverse from this formation, petrified cones (Spegazzini, 1924; Calder, sectors of the province of Santa Cruz: the central-eastern sector: 1953; Menéndez, 1960; Stockey, 1977, 1978; Stockey and Taylor, Cañadón de La Matilde, where the type locality is situated 1978), as well as silicified fungi (Singer and Archangelsky, 1957) (Criado Roque, 1953; Stipanicic and Reig, 1957; Panza, 1984, and wood, Agathoxylon matildense (Zamuner and Falaschi, 2005), 1995, 1998); the central sector, the best known from a paleonto- have been described from the well-known “Jaramillo Petrified logical point of view, comprising, among other localities, Forests,” including areas such as Cerro Madre e Hija and Cerro the “Monumento Natural Bosques Petrificados de Jaramillo” Cuadrado, among others. (Jaramillo Petrified Forest National Park) (Panza, 1982, 1995, In previous studies of the xyloflora from the Gran Bajo de 1998); the central and south-western sector (Bajo El Puma and San Julián sector, taxa of the order Coniferales were described: estancia Manantial Espejo, among other localities) (Panza, 1986; Protelicoxylon Philippe and Herbstiloxylon Gnaedinger, related to De Barrios, 1989; Panza and Marín, 1996; Panza and Cobos, members of the Cupressaceae; Circoporopitys Gnaedinger, two 1998); and the Gran Bajo de San Julián sector comprising local- new species of Podocarpoxylon Gothan, and Circoporoxylon ities such as Laguna del Molino, Laguna del Carbón, Mina del Kräusel, belonging to the Podocarpaceae; and Planoxylon Stopes, Gobierno, Mina La Pareja and Puesto Raspuzzi, among others of the group Protopinaceae. Specimens of Prototaxoxylon Kräusel (Panza and De Barrios, 1989; Panza and Irigoyen, 1995). and Dolianiti of the order Taxales, and Ginkgomyeloxylon tanzanii Herbst et al. (1995) found new outcrops containing large Giraud and Hankel of the order Ginkgoales, also have been quantities of petrified logs in the Gran Bajo de San Julián sector, described (Gnaedinger and Herbst, 2006; Gnaedinger, 2007a, b, which show the same characteristics as those from the north of 2012).

Downloaded from https://www.cambridge.org/core. IP address: 177.204.168.204, on 03 Apr 2018 at 16:29:38, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/jpa.2017.145 2 Journal of Paleontology

Figure 1. (1) Map showing the location La Matilde Formation of the Santa Cruz Province in Argentina. (2) Map showing the location Bajo El Puma and Gran Bajo San Julián sector (arrows). (3) Geologic map of the Gran Bajo San Julián sector, the circle shows the location of the localities. (Adapted from Gnaedinger and Herbst, 2006).

Figure 2. Gran Bajo San Julián localities. (1) Barda Blanca locality showing carbonaceous pelitic levels (arrow); (2) wood “in situ” from Barda Blanca locality; (3) Cerro Conito locality; (4) wood “in situ” from Cerro Conito locality.

In this contribution, Agathoxylon species are described for Morton and Herbst, 2001; Baez and Nicoli, 2003) are associated the first time from the Gran Bajo de San Julián sector (northern in these levels. The rest of the abundant wood is distributed part of Estancia Meseta Chica, Barda Blanca, Cerro Conito, throughout the formation. The base of the Bahía Laura Group Laguna La Guadalosa, and the south-east border of Laguna del is either the Roca Blanca Formation (Lower Jurassic) or the Carbón) and the central and south-western sector (Bajo El Bajo Pobre Formation (probably Aalenian–Bajocian) (Panza Puma), collected from the Middle Jurassic of the La Matilde and Irigoyen, 1995). The top is constituted by a series of brown Formation in Argentina. clays (San Julián Formation), which, because they contain a fossil flora of angiosperm leaves, would be assigned to the Geological setting Cenozoic (De Giusto, 1955; Bertels, 1977; De Giusto et al., 1980). The La Matilde Formation is part of the Bahía Laura Group The age of the Bahía Laura Group is still subject to some and is widely distributed in the province of Santa Cruz dispute. In modern times, by means of radiometric dating, dif- (De Barrios et al., 1999, fig. 28, p. 513) (Fig. 1). The specimens ferent authors have offered different age data, but all coincide analyzed come from the Gran Bajo San Julián, central, and between 157 Ma and 162 Ma ± 5–10 Myr; this means the La south-western areas (Fig. 1.2). In the Gran Bajo San Julián Matilde Formation can be assigned to the Bathonian interval up sector, the La Matilde Formation comprises ~70–80 m of to the Callovian (Spalletti et al., 1982; De Barrios, 1993; tuffs, sometimes sandy tuffites, lithic tuffs (tufolites), and Echeveste et al., 2001). chonites of greatly varied coloration, generally in tabular strata; Paleoenvironmentally, the La Matilde Formation sedi- also present are very subordinate amounts of fine-grained ments indicate that it is a continental sequence, characteristic, in conglomerates. part, of a low-energy fluvial environment; in the flood plains, There are also carbonaceous pelitic levels, up to true coals, some bodies of water (lagoons) formed in some areas that partly which are generally located near the base of the sequence came to be of marsh conditions (lentic and reducing). In the cropping out in the Gran Bajo de San Julián sector, particularly region, an intense volcanism developed, producing the exten- in the Laguna del Carbón and Barda Blanca localities (Figs. 1.3, 2). sively distributed ash and other pyroclastic products that con- Woods and some other fossil conchostracans, pelecypods, stitute the bulk of the sediments (Mazzoni et al., 1981; De insects, and anurans (Stipanicic and Reig, 1957; Gallego, 1994; Barrios et al., 1999).

Materials and methods 1964 Dadoxylon agathioides Kräusel and Jain, p. 59, pl. 1, figs. 1–3, pl. 3, figs. 14, 15, text-figs. 1, 4. The specimens described come from the La Matilde Formation, 1974 Araucarioxylon agathioides (Kräusel and Jain); Bose Santa Cruz Province, Argentina, (Fig. 1.1) and were collected from and Maheshwari [seen in Yadav and Bhattacharyya, the Bajo El Puma locality of the central and south-western sector 1996, p. 59]. and another four localities from the Gran Bajo de San Julián sector: Laguna La Guadalosa (Estancia El Mineral), Cerro Conito, Barda Holotype.—24288/255 B.S.I.P. from Mandro, Rajmahal Hills, Blanca and the northern part of Estancia Meseta Chica (Estancia Bihar, India (Jurassic). Meseta Chica), and the south-east border of Laguna del Carbón (Estancia La Silvita) (Figs. 1.2, 3). The in situ petrified woods and Description.—Several fragments of silicified wood found in situ rolled trees reach diameters of up to 2.4 m (Fig. 2). in the Barda Blanca, Cerro Conito, and Laguna La Guadalosa Fragments of silicified wood showing good cellular pre- localities from the Gran Bajo de San Julián sector and Bajo El servation were analyzed. Standard petrographic thin-sections Puma locality (Figs. 1, 2) of the central and south-western sector were prepared for the wood fragments oriented along three were analyzed. The logs found in situ measure up to 1.50 m in planes: radial longitudinal (RLS), tangential longitudinal (TLS), diameter, and one of the logs reaches up to 4 m long by 1.10 m in and transverse (TS). In addition, techniques based on acetate diameter. Specimen CTES-PB 10647 has a wavy external peels and dissociated material (Jones and Rowe, 1999) also appearance due to the effects of pressure during fossilization, were employed. Thin-sections were studied in detail under a because in making the conventional cuts it is observed that in the Leica microscope (DM500) and microphotographs were taken same section it shows a mixture of longitudinal radial and tan- by digital camera (Leica ICC50) with Leica Application Suite gential and cross-sections. All specimens correspond to pyc- EZ 3.2.3 software and a scanning electron microscope (SEM noxylic wood, decorticated and with good preservation of the Jeol 5800LV) at the Universidad Nacional del Nordeste (Cor- secondary xylem. The description is based on the specimen rientes, Argentina). from the Barda Blanca locality (CTES-PB 10659), although The wood has been described in accordance with the list examination of the other specimens supports it (Tables 1, 2). of microscopic features for softwood identification (García This specimen, in TS, does not show growth rings nor are they Esteban et al., 2002, 2003; Richter et al., 2004). Greguss’s (1955) observed with the microscope, even though at first glance they glossary of terms and the standard measurements established by are apparently well marked, which is due to the presence of Chattaway (1932) are followed. At least 20 individual measure- “shearing zones” sensu Erasmus (1976) (Fig. 3.1). In TS, the ments of the various anatomical elements were recorded, tracheids have rectangular-quadrangular to polygonal outlines. giving values for means, maxima and minima, and occasionally The radial diameter of the tracheids is 31 μm (15–37 μm) and the the maximum number established (e.g,. 42 µm[25–66 µm] or tangential is 33 μm (22–45 μm). The average number of rows of 3–14 [35] cells). tracheids separating the rays is 4, with a range of 1–11. The rays Systems of nomenclature and nomenclatural reviews are are presented in a non-continuous way through the section those found in Bamford and Philippe (2001) and Philippe and (Fig. 3.1). In RLS, the wood type (tracheid radial pitting) is Bamford (2008). araucarian (100% of the contiguous pits are araucarioid). Pits are bordered, uniseriate, and flattened (35% [32–38%]) biseri- – — ate, hexagonal, and alternate (32% [29 37%]), and occasionally Repository and institutional abbreviations. Specimens and triseriate or bi-triseriate, hexagonal, alternate, or opposite (0.4% microscopic slides are deposited in the paleontological collec- [0–1%]). In addition, they are uniseriate, with biseriate portions tion of the Universidad Nacional de Nordeste (UNNE) – fl “ ” (32% [30 36%]), attened, and hexagonal, alternate (23% Dr. Rafael Herbst Paleobotany Section (CTES-PB) and [21–25%]) and opposite in a single pair (8% [6–12%]) or in (CTES-PMP), Corrientes, Argentina. several pairs (1% [0–2%]). Rare groups of 6–10 pits are recognized; they start and end with a single pit and have portions Systematic paleobotany without pitting in the walls of the tracheids. The size of the biseriate pits is 15 x 15 μm and the uniseriate pits are 15 x Order Coniferales Engler, 1897 11 μm. The aperture is cross-like (internal and external elliptical Family Araucariaceae Henkel and Hochstetter, 1865 aperture), measuring 15 x 4 μmor11x4μm, or circular mea- Genus Agathoxylon Hartig, 1848 suring 7.5 μm (Figs. 3.2, 3.3, 3.4, 3.5, 4.1, 4.2). Cross-fields – — show an araucarioid type arrangement, with 2 6 araucarioid pits Type species. Agathoxylon cordaianum Hartig, 1848, p. 188. (circular aperture) or cupressoid pits (elliptical aperture) whose – Remarks.—According to the criteria of Bamford and Philippe frequency range is 4 6, arranged in groups or in horizontal or fi – (2001), Philippe and Bamford (2008), and Rößler et al. (2014), vertical rows. In some marginal cross- elds, 7 8 pits can be the genus Agathoxylon Hartig has nomenclatural priority over observed (Fig. 3.6, 3.7). In TLS, the radial system is homo- the genera Araucarioxylon and Dadoxylon; hence, the La geneous, with homocellular, uniseriate rays (84%), and some – Matilde Formation specimens are assigned to Agathoxylon partially biseriate rays with 1 3 cells (16%). The height ranges – Hartig. from 1 22, 37 cells, with an average of seven cells. The radial end cells are elliptical and the central ones are rectangular- Agathoxylon agathioides (Kräusel and Jain) new combination ovoid, and they measure 26 x 22 μm, 30 x 26 μm, or 34 x 30 μm Figures 3, 4.1, 4.2. in width and height. In tangential and radial section, the

Figure 3. Agathoxylon agathioides.(1) TS, detail of the tracheids; (2–5) RLS, pits on tracheid radial walls; (6, 7) RLS, detail of cross-ﬁeld pits; (8, 9) TLS, rays; (8) biseriate rays produced as a reaction to vascular cambium damage. Scale bars: (1) = 150 µm; (2–7) = 30 µm; (8, 9) = 110 µm. (1, 2, 4, 6–9) CTES PB 10659. (3, 5) CTES PB 14236.

Figure 4. (1, 2) Agathoxylon agathioides.(3–5) Agathoxylon santalense.(6–8) Agathoxylon termieri.(1–4, 6) RLS, pits on tracheid radial walls; (5–8) RLS, detail of cross-ﬁeld pits (white arrows). Scale bars: (1, 2) = 30 µm; (3–5) = 40 µm; (6–8) = 35 µm. (1, 2) CTES PB 10659. (3–5) CTES PB 10649. (6–8) CTES PB 10693.

Table 1. Quantitative data expressed in percentages; the following characters are combined: seriations radial pitting tracheids (column 1), type and shape of radial pitting tracheids (column 2: lineal schemes). M-M (m) = Minimum-Maximum (mean). Agathoxylon agathioides A1 = CTES-PB 10659; A2 = CTES-PB 10647; A3 = CTES-PB 14236; A4 = CTES-PB 10703; A5 = CTES-PB 10702; A6 = CTES-PB 12036; Agathoxylon santalense B1 = CTES-PB 10649; B2 = CTES-PB 14239; B3 = CTES-PB 10665; Agathoxylon termieri C1 = CTES-PB 10693; C2 = CTES-PB 10696; C3 = CTES-PB 10675; C4 = CTES-PB 12043; C5 = CTES-PB 12041; Agathoxylon santacruzense D = CTES-PB 12012.

Characters/specimen M-M M-M M-M M-M A1 A2 A3 A4 A5 A6 B1 B2 B3 C1 C2 C3 C4 C5 D (m) (m) (m) (m) 42–60 6 7 6–9 51 56 54 58 60 9 (52) (7) 1 30–39 10–19 1–4 32 35 38 33 37 30 39 38 10 20 18 14 18 19 3 1 4 (34.8) (16.5) (2.6)

12–19 21–24 16 14 18 15 12 22 21 24 (15) (22) 21–28 14–20 5–8 21 23 25 28 21 25 24 24 15 17 19 20 15 14 5 6 8 (6) (24.2) (16.6) 5–7 1–3 1/2 7 7 5 6 7 2 3 1 (6.4) (2) 4–11 9 6–13 3–5 7 12 6 4 6 10 8 6 9 11 13 8 6 5 4 3 (8.2) (9) (4) 1–3 1–2 4 2–4 2 1 1 0 2 1 1 2 3 2 1 2 1 (2) 3 2 3 (3)

19–33 29–36 24 22 21 20 19 29 36 33 (32.6) (26) 2 29–34 52 46–60 10–15 37 29 30 34 32 33 27.5 28.7 60 47.5 46 53 60 15 10 11 (31.7) (54) (12)

1–2 1–2 2 1 2 1 2 1 2 1 (1.5) (1) 3 0–3 0.5–2 5–8 1 0 0 1 2 1 0.5 1.3 3 2.5 3 3 0 3 (2.4) 5 8 6 (0.98) (6)

tracheids are recognized with resins, generally distributed near cross-like shape of the opening of the pits and similar grouping the rays. The resins occupy the entire wall of the tracheids in the of the pits in the radial walls of the tracheids, but this latter form of resin plates. In some areas, fully biseriate rays can be character is also observed in some species of Araucaria Juss observed, probably produced as a reaction to vascular cambium (Kräusel and Jain, 1964). damage (Fig. 3.8, 3.9). The rameal and/or foliar traces are Tables 1 and 2 summarize the observed characters of six elliptical and measure 750 μm long, with some preserved trac- specimens from the La Matilde Formation, and quantitative data heids 7.5–15 μm in diameter. from three different portions of the early wood in sample CTES- PB 10659 are given. In the same data, it is possible to appreciate Materials.—Gran Bajo de San Julián sector: Barda Blanca: a certain uniformity in the percentages of the different CTES-PB 10647 (CTES-PMP 2324-2325); CTES-PB10659 combinations of the pits of the radial walls of the tracheids, (CTES-PMP 2353 a, b, c); CTES-PB 14236 (CTES-PMP 3535 but with a predominance of uni-biseriate pits. In addition, a, b, c); CTES-PB 14237 (CTES PMP- 3536 a, b, c); CTES-PB variability is observed in the number of pits in the cross-fields, 14238 (CTES-PMP 3537 a, b, c). Cerro Conito: CTES-PB but, always within the range of 2–8, some arranged in groups of 10702 (CTES-PMP 2426 a, b, c); CTES-PB10703 (CTES-PMP 5–6, as in a specimen from India (Kräusel and Jain, 1964). Also, 2386 a, b, c). NW Laguna La Guadalosa: CTES-PB 12033 it reflects differences in the height of the rays, with the Patagonia (CTES-PMP 2372 a, b, c); CTES-PB 12034 (CTES-PMP 2365 specimens occasionally exhibiting up to 40 cells. a, b, c); CTES-PB 12035 (CTES-PMP 2366 a, b, c); CTES-PB These differences do not invalidate the assignment of the 12036 (CTES-PMP 2369 a, b, c). Central and south-western specimens described here to Agathoxylon agathioides because sector: Bajo El Puma: CTES-PB 14208 (CTES-PMP 3532 a, b, c); they agree with most of the diagnostic characters. Agathoxylon CTES-PB 14209 (CTES-PMP 3533 a, b, c); CTES-PB 14210 agathioides (Kräusel and Jain) n. comb. is comparable to several (CTES-PMP 3534 a, b, c). species of Araucarioxylon, Agathoxylon, and Dadoxylon from Gondwana owing to the presence of hexagonal araucarioid pits, Remarks.—The description above coincides with the characters but it is identifiable by the presence of clusters of groups of pits given by Kräusel and Jain (1964) for the taxon Dadoxylon and by the set of diagnostic characters (Table 3). agathioides. These materials are characterized by araucarian secondary wood types with mostly uniseriate to biseriate, some Agathoxylon santalense (Sah and Jain) new combination triseriate, alternate, flattened, and hexagonal radial pitting. Fur- Figures 4.3, 4.4, 4.5, 5 thermore, they are arranged in groups over short distances of fi one to several pits, with rays of 2–20 cells in height and cross- 1964 Dadoxylon santalense Sah and Jain, p. 178, pl. 2, g. 11, fi – fi fields with 2–8 pits arranged in an araucarioid pattern (Kräusel pl. 3, gs. 15 18, text. gs. 9, 10. and Jain, 1964). The specific epithet of this species comes from 1974 Araucarioxylon santalense (Sah and Jain); Bose and Kräusel and Jain’s (1964) comparison of this wood with some Maheshwari [seen in Yadav and Bhattacharyya, 1996, species of the genus Agathis Salisb, noting that they shared the p. 59].

– Holotype.—4506 B.S.I.P. from Mandro, Rajmahal Hills, Bihar, India (Jurassic). 27.5 95 92 46 – – – CTES-PB 6.4 8 (m) D 10 20 M-M — = Description. Wood fragments found in situ of 95 cm in dia-

43 meter, and a trunk of 1.20 m long and 30 cm in diameter were CTES-PB 10659; – 3 222 8 6.5 14 20 19.5 20

= studied. These materials come from the Barda Blanca locality of

A1 the Gran Bajo de San Julián sector and Bajo El Puma locality of — — — — CTES-PB 12012. the central and south-western sector (Figs. 1, 2). The description = is based on specimen CTES-PB 10649, although examination of D —— 19

CTES-PB 14239; B3 the other specimens supports it. Secondary xylem is pycnoxylic =

44 with distinct growth ring boundaries, and the transition from – early wood to late wood is gradual. In TS, the tracheids are quadrangular-rectangular and irregular in shape. The radial 43 –

77 567 μ – μ —— diameter of the tracheids is 59 m (45 82 m) and the tangential Agathoxylon agathioides 100 100 100 100 100 100 66 is 50 μm (30–75 μm). The average number of tracheids separat- – 703331 6370 35321 67 2121 32 66 32 69 75 30 23 68 30.4 29 63.5 25 9 86 93 93 95 94 93 93 557 76213 56 2121.81 1015 12 12 10 14 14 11.6 16 43 688 7 ing the rays is 10, with a range of 3 26 tracheids. The rays are – – – – – – – – – – – – (m)C1C2C3C4C5 CTES-PB 10649; B2 M-M

Agathoxylon santacruzense displayed in a continuous way through the section (Fig. 5.1). In =

42 RLS, the wood secondary type (tracheid radial pitting) is arau- – B1 8 8 10 10 carian (100% of the contiguous pits are araucarioid). In the early

42 wood, pits are bordered, uniseriate, ﬂattened (16% [10–20%]), – biseriate, hexagonal, and alternate (53% [46–60%]), and occa- 42 CTES-PB 12041; – sionally triseriate or bi-triseriate, hexagonal, and alternate (3% —— Minimum-Maximum (mean). = [2.5–3%]); in addition, they are uniseriate, with biseriate por- = tions (30% [27–33%]), ﬂattened and hexagonal, alternate (17% 69 7040 67 3055 69 33 2951 31 28 68 67 2 31 70.5 30 3 66 28 1.5 66 3 1.5 62 96 85 86 84 84 84554 21221 2240 8 12 9 12 10 15 12 8 10 10 15 14 16 15 – (63)– (36.5)– (51)– (48)– (68) (31) (29) (68) – – (1) (2.5) – (6.8) – – – – (8) (92)– (85)

(m) B1 B2 B3 – –

M-M [15 19%]) and opposite in a single pair (11% [9 13%]) or in a Agathoxylon santalense several pairs (2% [1–3%]). In the late wood, pits are bordered, 64

– uniseriate and ﬂattened. The size of the pits is 15–30 μmx 88 28 28 15 μm. The pits present a central circular aperture, which mea- 64 – CTES-PB 12043; C5 sures 6–7.5 μm (Figs. 4.3, 4.4, 5.2, 5.3). Cross-ﬁelds show an — = araucarioid type arrangement, with 2–6 araucarioid pits, mea- CTES-PB 12036; 64 –

—— μ μ = suring 11 m with a circular aperture of 4 m, whose frequency range is 3–4, arranged in groups or in horizontal rows. In some 64 –

810 ﬁ –

40 marginal cross- elds, 9 12 pits can be observed (Figs. 4.5, 5.4).

64 In TLS, the radial system is homogeneous with homocellular – — rays, uniseriate, of 1–8, 12 cells in height, with an average of

CTES-PB 10675; C4 – – μ 64 4 5 cells. The central cells are ovoidal and measure 15 30 mx – =

—— – μ CTES-PB 10702; A6 22 30 m in width by height, respectively. Tracheids are

= observed with resins associated with the rays, which in radial and tangential section form the typical biconcave plates or “resin plates” (Fig. 5.5).

Materials.—Gran Bajo de San Julián sector: Barda Blanca: CTES-PB 10696; C3 Hexagonal1-seriate 63 67 61 51 69 49 60 52 60 48 60 55 54.7 48 Circular Flattened2 seriate 363 seriate 33 39 48 31 50 0.5 40 46 1 40 51 2 31 43.5 1 44 43 0.5 1.3 0.4 Alternate 90 96 92 90 91 92 90 en768776 6 Mean Minimum 1 1 2 2 2 2 1 MaximumOccasional maximum 37 22 16 20 21 18 20 16 Frequency range 4 aiu 666666 6 665 5 MinimumMaximum Occasional maximum 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Opposite 9.6 4 8 10 9 8 4

= CTES-PB 10649 (CTES-PMP 2328-2329); CTES-PB10665

CTES-PB 10703; A5 (CTES-PMP 2321 a, b, c), CTES-PB 14239 (CTES-PMP 3538 = a, b, c); CTES-PB 14240 (CTES-PMP 3539 a, b, c); Center and south western sector, Bajo El Puma: CTES-PB 14206 (CTES- PMP 3530 a, b, c); CTES-PB 14207 (CTES-PMP 3531 a, b, c).

— CTES-PB 10693; C2 Remarks. After comparison with species of the genera

= Araucarioxylon and Dadoxylon, the specimen from the La (number of cells) CTES-PB 14236; A4 C1 Seriation Shape Arrangement in multiseriate Matilde Formation was determined to be Agathoxylon santa- = lense (Sah and Jain) n. comb. This species was erected by Sah and Jain (1964) as Dadoxylon santalense and is characterized by araucarian wood types with mostly uniseriate, sometimes biseriate, alternate, flattened, and hexagonal radial pitting; (in percentage) cross-fields with 2–6 pits arranged in an araucarioid pattern, Quantitative data of the anatomical characteristics examined type radial pitting (contiguity) araucarioid. M-M (m) Agathoxylon termieri eld Number of pits usually four, with the aperture as big as the border and rays of 1– CTES-PB 10647; A3 fi

= 10 cells in height; and resin tracheids present, associated with 10665; A2 Radial pitting Table 2. Characters Specimens A1 A2 A3 A4 A5 A6 Rays Ray height Cross- the rays (Table 3).

Table 3. (1, 2) Comparison between some species of Agathoxylon/Araucarioxylon/Dadoxylon from Gondwana sharing the characters: presence of ﬂattened and hexagonal and alternate (opposite) pits in the radial walls of the tracheids. (1/2: rays uniseriate partially biseriate; in parentheses = character with occasional condition).

RADIAL CROSS- RAYS RAYS CHARACTERS/SPECIES WALLS PITS FIELD WIDTH HEIGHT ORIGIN/REFERENCE AGE A. manieroi (Krausel and Dolianiti) 1–41–9 — 1–47 Brazil Upper Carboniferous Maheshwari Kräusel and Dolianiti, 1958; Maheshwari, 1972 A. gondwanense (Maithy) Maheshwari 3–4(1–5) 2–8 1 (1/2) 1–43 India Lower Permian Maithy, 1964; Maheshwari, 1972 A. ningahense (Maheshwari) Crisafulli 1–41–6 1 (2) 1–11 India, Antarctica, Uruguay, Argentina Upper Permian and Herbst Maheshwari, 1964; Crisafulli and Lutz, 1997; Lower Permian Crisafulli and Herbst, 2008 A. surangei Agashe, Prasad, and Suresh 1–41–11 1–21–35 India Permian Agashe et al., 1981 A. nummularium (Maniero) Maheshwari 1 (2) Numerous 1 (2) 1–30 Brazil, Uruguay Permian White, 1908; Maniero, 1946; Kräusel and Dolianiti, 1958; Maheshwari, 1972; Crisafulli, 2001 A. parbeliense (Rao) Maheshwari 1–58–91 1–24 India Permian Rao, 1935; Maheshwari, 1972 A. nadorii Vagyani and Raju 1–multiseriate 2–6 1 (2) 2–30 India Upper Permian Vagyani and Raju, 1981 A. roxoi (Maniero) Krausel and Dolianiti 1–22–4(5–6) 1 1–36 Brazil, Uruguay Upper Permian Maniero 1946; Kräusel and Dolianiti, 1958; Maheshwari, 1972; Crisafulli, 2001 D. sudanense Duperon-Laudoueneix and 2–3(1–4) 1–6 1 (1/2) 1–26 Africa Permian–Triassic Lejal-Nicol Duperon-Laudoueneix and Lejal-Nicol, 1981 A. africanum Bamford 2 (1) 2–71 2–18 South Africa Upper Permian– Bamford, 2000 Lower Triassic? A. karooensis Bamford 2 (1–3) 2–4 1 (2) 3–25 South Africa Upper Permian– Bamford, 2000 Lower Triassic? D. sudanense Duperon-Laudoueneix 1–51–4 1 (2) 1–26 Africa Permian–Triassic and Lejal-Nicol Duperon-Laudoueneix and Lejal-Nicol, 1981 D. parenchymatosum Vogellehner 2 (1) 3–4 1 (2) 2–12 South Africa Permian–Triassic Vogellehner, 1965 D. tordoxyloides Vozenin-Serra and 1 (2) 2–41 2–34 New Caledonia, Australia Permian–Triassic Salard-Cheboldaeff Vozenin-Serra and Salard-Cheboldaeff, 1992 D. agathiodes Krausel and Jain 1–2 (3) groups 2–8 1 (1/2) 2–20 India Lower Cretaceous Kräusel and Jain, 1964 A. agathioides (Kräusel and Jain) nov. comb. 1–2(3) groups 2–6,10 1(1/2) 1–22 (28–40) Argentina this work Middle Jurassic D. bindrabanense Sah and Jain 2–3 (1) 4–12 1 1–45 India Lower Cretaceous Sah and Jain, 1964 D.(A.) jurassicum Bardwaj 1–24–81 1–11 India Lower Cretaceous Bhardwaj, 1953 A. santalense 1–2 (3) 2–7 1 (2) 1–12 India Lower Cretaceous Sah and Jain Sah and Jain, 1964 A. santalense (Sah and Jain) n. comb. 1–2 (3) 2–6,8 1 1–8 (12–15) Santa Cruz, Argentina Middle Jurassic this work D. mandroense Sah and Jain EW: 1–3 WE: 4–12 11–15 India Lower Cretaceous LW: 1–2 LW: 2–6 Sah and Jain, 1964 A. mosurense Jeyasingh and Kumarasamy 1–2(3–4) 2–6 1 (1/2–3) 1–27 India Cretaceous Jeyasingh and Kumarasamy, 1995 Araucarioxylon sp. 1 Falcon-Lang and Cantrill 1–2 (3) 2–9 1 (2) 1–23 Antarctica Lower Cretaceous Falcon-Lang and Cantrill, 2001 Araucarioxylon sp. 2 1–32–8 1 (2) 1–11 Antarctica Lower Cretaceous Falcon-Lang and Cantrill Falcon-Lang and Cantrill, 2001 A. resinosum (Shulka) Trivedi and Srivastava 1–41–10 1–21–39 India Cenozoic Shukla 1944; Trivedi and Srivastava, 1989 A. shuklai (Singhai) 1–2,3 1–21 2–30 India Cenozoic Trivedi and Srivastava Singhai 1958; Trivedi and Srivastava, 1989 A. chhindwarensis (Billimoria) Trivedi and 1–31–71–2 — India Cenozoic Srivastava Billimoria, 1948; Trivedi and Srivastava, 1989 A. mohgaoensis Lakhanpal, Prakash, and Bande 2 (1–3) 1–21 2–15 (–30) India Cenozoic Lakhanpal et al., 1977 A. pichasquense Torres and Rallo 1–23–14 1 (1/2) 1– 14 (–25) Chile Upper Cretaceous– Torres and Rallo, 1981; Nishida et al., 1992 Cenozoic A. kellerense Lucas and Lacey 1–31–5 1 (1/2) 1–15 (–25) Chile. Lucas and Lacey, 1981 Upper Cretaceous– Antarctica. Nishida et al., 1992 Cenozoic A. antarcticus (Poole and Cantrill) Pujana, 1–21–91 1–16 Antarctica Paleocene Santillana, and Marenssi Pujana et al., 2015 A. pseudoparenchymatosum (Gothan) Pujana, 1–21–71 1–7 Antarctica Paleocene Santillana, and Marenssi Pujana et al., 2015

This assignment is supported, essentially, by the type and This species is similar to Araucarioxylon/Dadoxylon and number of pits in the cross-ﬁelds, by the height of the rays, Agathoxylon in the presence of uniseriate, ﬂattened, and bi- and resin in the tracheids. The Argentine material differs in triseriate, hexagonal, mainly alternate, radial pitting; the differences having rarely triseriate radial pitting; resins in the radial cells as are given in the set of diagnostic characters and the same are well as in the tracheids associated with the rays; and because it expressedinTable3.Araucarioxylon santalense is very similar to shows a higher percentage of biseriate radial pitting in the early Araucarioxylon sp. described by Falcon-Lang and Cantrill (2001) wood. In comparison, a specimen from India has mostly in most of the anatomical characters (Table 3), and to uniseriate pits, which would probably correspond mostly to Araucarioxylon hoodii, described by Tidwell and Medlyn (1993) late wood. from the Upper Jurassic Morrison Formation (Utah, USA). The

Figure 5. Agathoxylon santalense.(1) TS, detail of the tracheids and growth ring; (2, 3) RLS, pits on tracheid radial walls; (4) RLS, detail of cross-ﬁeld pits; (5) TLS, rays and resin plates. Scale bars: (1) = 140 µm; (2–4) = 40 µm; (5) = 130 µm. (1–4) CTES PB 10649. (5) CTES PB 14239.

latter is distinguished by the presence of pits in the tangential walls Description.—Fragments of fallen wood, one of them 3 m long of the tracheids, the shape and number of pits in the cross-field, and and 30 cm in diameter and another 1.3 m in diameter, were the greater height of the rays. analyzed from the Cerro Conito and northern part of the Estancia Meseta Chica localities from the Gran Bajo de San Agathoxylon termieri (Attims) Gnaedinger and Herbst, 2009 Julián sector. The following description is based on specimen Figures 4.6, 4.7, 4.8, 6 CTES-PB 10693 and consists of a fragment of secondary xylem, 1965 Dadoxylon (A.) termieri Attims, p. 33. pycnoxylic, with growth ring boundaries distinct and with a gradual transition from the early wood to the late wood. In TS, the 1985 Dadoxylon (A.) termieri Attims in Giraud and Hankel tracheids of the early wood are polygonal with a thickness of the p. 170, pl. 2, fig. a–e, text-fig. 3. double wall of 7.5 μm. The radial diameter of the tracheids is 2000 Araucarioxylon allani (Kräusel) Maheshwari in 54 μm(37–75 μm) and the tangential 42 μm(22–67 μm). The Gnaedinger, p. 38. tracheids of the late wood are generally of rectangular outline, 2006 Araucarioxylon termieri Gnaedinger, p. 171, figs. 1, 2. some polygonal. The radial diameter of the tracheids is 31 μm (22–37 μm) and the tangential is 43 μm(30–60 μm). The average — Holotype. QDS 226/3 from Lias (Lower Jurassic), Morocco. number of tracheids that separate the rays is 6, varying between 1 and 17 tracheids (Fig. 6.1). In RLS, the wood type (tracheid Cotype.—78-1 from Tanzania (Lower Jurassic). radial pitting) is araucarian (100% of the contiguous pits are

Figure 6. Agathoxylon termieri.(1) TS, detail of the tracheids and growth ring; (2–5) RLS, pits on tracheid radial walls; (6–8) RLS, detail of cross-ﬁeld pits; (9, 10) TLS, rays. Scale bars: (1) = 140 µm; (2) = 100 µm; (3–7) = 20 µm; (8, 9) = 10 µm; (10) = 50 µm. CTES PB 10693.

araucarioid). Pits are circular (100%), araucarioid, uniseriate Paratype.—CTES-PB 12013, CTES-PMP 2434 a, b, c. (51%), alternate biseriate (24%), uniseriate partially biseriate, alternate (16%) and opposite (7%), and triseriate and bi-triseriate, Diagnosis.—Wood type (tracheid radial pitting) is araucarian alternate (2%). The size of the pits is 11–15 μmx11–15 μm. The (100% of the contiguous pits are araucarioid). Pits are araucar- pits exhibit a circular aperture, which measures 7.5 μm(Figs.4.6, ioid, uniseriate, flattened, and circular; alternate biseriate, circular, 6.2, 6.4, 6.5). Cross-fields are araucarioid, having 2–8, 10 pits that and hexagonal; uniseriate, partially biseriate, alternate, circular, are circular, with circular or sometimes elliptical apertures, whose hexagonal-flattened; and opposite circular, hexagonal-flattened in frequency range is 3–4 pits, arranged in groups or crown-shaped a pair or several pairs (japonicum type); and triseriate and bi- or in two or three horizontal rows (Figs. 4.7, 4.8, 6.6–6.8). The triseriate, alternate circular and hexagonal. Cross-fields are arau- pits measure 12–15 μm in diameter and the apertures from 4 μm carioid, with 2–14, 20 pits, circular, with elliptical or sometimes to 11 μm; some of the radial cells end in a pointed shape. In TLS, circular apertures, whose frequency range is 6–8 pits, arranged in the radial system is homogeneous with homocellular rays, uni- disordered groups or crown-shaped or some in two or four hor- seriate, of 1–12 cells in height; the average is 4–5 cells. The cells izontal rows. The rays are homogeneous, mostly uniseriate, and at both ends are elliptical and the centers are rectangular or the height in number of cells is 1–16, 20. quadrangular, measuring 15–52 μmhighby15–30 μm wide. In addition, the rays show differences in the height of the central Occurrence.—La Matilde Formation, Santa Cruz Province, radial cells of the same rays; some radial cells measure 17–20 μm Argentina (Middle Jurassic). and others 6–11 μm (Figs. 6.9, 10). Description.—Fragments of logs found in situ of 1.5 m in diameter, with 1 m height preserved, and a fallen trunk with visible Materials.—Gran Bajo de San Julián sector: Cerro Conito: dimensions of 1.50 m in length and 60 cm in diameter were CTES-PB 10675 (CTES-PMP 2408-2409); CTES-PB 10693 studied. These materials came from the southeastern border of (CTES-PMP 2381); CTES-PB 10696 (CTES-PMP 2391); Laguna del Carbón locality. The following description is based CTES-PB 10697 (CTES-PMP 2392); CTES-PB 12004 (CTES- on specimen CTES-PB 12012, which consists of a fragment of PMP 2390); CTES-PB 12017 (CTES-PMP 2438); CTES-PB secondary xylem, pycnoxyilic, with distinct growth rings. In TS, 14265 (CTES-PMP 3540 a, b, c); CTES-PB 14266 (CTES-PMP 3541 a, b, c); Northern part of Ea. Meseta Chica: CTES-PB the tracheids of the early wood are rectangular-ovoidal and 12041 (CTES-PMP 2459); CTES-PB 12043 (CTES-PMP 2465- polygonal in the shape. Tracheids of the early wood have an average radial diameter of 47 µm(36–60 µm) and tangential dia- 2466); CTES-PB 12052 (CTES-PMP 2472). meter of 37 µm(24–52 µm). In the late wood, the tracheids have a tangential average diameter of 35 µm(24–40 µm) and radial dia- Remarks.—Specimens identified as Araucarioxylon termieri meter of 21 µm(16–28 µm). The average number of tracheids that (Attims) Gnaedinger and Herbst match with the description made separate the rays is 7–8, varying between 2–18 tracheids. The by Giraud and Hankel (1985) for Dadoxylon (Araucarioxylon) rays are presented in a continuous way through the section termieri Attims and with the anatomical characters of the holo- (Fig. 7.1). In RLS, the wood type (tracheid radial pitting) is ara- type given by Attims (1965) (see Giraud and Hankel, 1985). In ucarian (100% of the contiguous pits are araucarioid). Pits are addition, these specimens from Argentina show differences in the araucarioid, uniseriate (9.6% [7–12%]), flattened (2.6% [1–4%]), height of the central radial cells within the same ray, as in the and circular (7% [6–9%]); alternate biseriate (44.6% [39–51%]), specimen from Tanzania (Giraud and Hankel, 1985, pl. 13, circular (32.6% [29–36%]), and hexagonal (12% [10–15%]); fig. 3). Tables 1 and 2 summarize the observed anatomical fea- uniseriate partially biseriate (37% [36–38%]), alternate, circular tures of five samples from the La Matilde Formation and show the (22% [21–24%]), hexagonal-flattened (6% [5–8%]), and opposite numerical differences in the percentages of the seriation and circular (2% [1–3%]), hexagonal-flattened in a pair (4% [3–5%]) combination of the radial pitting, but, always with a greater per- or in several pairs (japonicum type) (3% [2–4%]); and triseriate centage of uniseriate pits, like the specimens from Africa. and bi-triseriate, alternate circular (1% [1–2%]) and hexagonal Araucarioxylon termieri (Attims) Gnaedinger and Herbst is (6% [5–8%]). The size of the pits is 12–16 μmand20μmx similar to other species of Agathoxylon (Araucarioxylon)from 10 μm. The pits present a circular aperture, which measures Gondwana in sharing the presence of circular pits in the radial 4–6 μm (Figs. 7.2–7.5, 8.1–8.4). Cross-fields are araucarioid, walls of the tracheids, and is distinguished by the seriation and having 2–14, 20 pits that are circular, with an elliptical or some- distribution of pits in the radial tracheid walls, the number of pits in times circular aperture, whose frequency range is 6–8pits, the cross-fields, and the ray height (Table 4). However, A. termieri arranged in disordered groups or crown-shaped or some in two or is identical to the Permian species Araucarioxylon allani (Kräusel) four horizontal rows. The pits measure 8–10 μmandtheapertures Maheshwari in presenting in the radial walls of the tracheids are elliptical measuring from 4–8 μmx3μmorcircularand araucarioid, circular, uniseriate, biseriate, and rarely triseriate pits, 2.5–4 μm (Figs. 7.5–7.7, 8.1–8.5). The rays are homogeneous and uniseriate, low rays, with a height of 1–12 cells (Kräusel, 1962) and most uniseriate, the height in number of cells is 1–16, 20, the (Table 4); and, therefore they are probably synonymous. average is 6 cells. The cells at both ends are elliptical and the centers are rectangular or quadrangular, measuring 15–52 μm Agathoxylon santacruzense new species high x 15–30 μm wide (Fig.7.8). Figures 7, 8 Etymology.—In reference to Santa Cruz province, Argentina, Holotype.—CTES-PB 12012, CTES-PMP 2433 a, b, c. where the analyzed wood was found.

Table 4. Comparison between some species of Agathoxylon/Araucarioxylon from Gondwana sharing the characters: presence of circular pits (some ﬂattened) and alternate (opposite) in the radial walls of the tracheids. (1/2: rays uniseriate partially biseriate; in parentheses = character with occasional condition).

RAYS RADIAL CROSS- CHARACTERS/SPECIES WALLS PITS FIELD WIDTH HEIGHT ORIGIN/REFERENCE AGE A. vesturense Agashe and Prasad 1–41–9, 13 1 (2) 1–26 India Permian Agashe and Prasad, 1989 A. zaranense Agashe and Prasad 1–41–8 1 (2) 1–21 India Permian Agashe and Prasad, 1989 A. bengalense (Holden) Maheshwari 1–3 (4) 2–71 1–20 India Permian Holden, 1917; Maheshwari, 1972 A. meyenii Agashe and Gowda 1–41–11 1 (1/2) 1–18 (–26) India Permian Agashe and Gowda, 1978 A. allanii (Kräusel) Maheshwari 1–2 (3) groups 1–6, 8 1 1–12 Antarctica, Permian Kräusel, 1962 A. allanii (Kräusel) Maheshwari 1–2(3–4) 2–6, 12 1 1–27 Antarctica Permian Maheshwari, 1972 A. allanii (Kräusel) Gnaedinger and herbst 1–22–41 3–9(–12) Uruguay Lower Permian Crisafulli et al., 2009 A. allanii (Kräusel) Maheshwari 1–22–41 3–9 Argentina, Permian Crisafulli et al., 2000 A. petriellae Zamuner 2–3(1–4) 9–20 1 (1/2) 1–21 Uruguay Lower Permian Zamuner, 1996 A. malaimbandense (Marguerier) Gnaedinger and Herbst 1–21–6 1 (1/2) 1–23 Africa Upper Permian Marguerier, 1976 Lower Triassic Araucarioxylon sp. McLoughlin. 1992 1–2(3) 1–21–22–34 Australia Upper Permian McLoughlin, 1992 A. kumarpurensis Bajpai and Singh 2 (1.3–4) 2–8 1 (1/2) 1–19 India, Upper Permian Bajpai and Singh, 1986 A. kumarpurensis Bajpai and Singh Africa, Roberts et al., 1997 A. kumarpurensis (Bajpai and Singh) Crisafulli and Herbst 1–34–81 1–12 Argentina Lower Permian Crisafulli and Herbst, 2008 A. kumarpurensis (Bajpai and Singh) Crisafulli and Herbst 1 (2) 4–71 3–9 Uruguay Lower Permian Crisafulli et al., 2009 A. lamaibandianus Crisafulli and Herbst 1–21–41 3–23 Argentina Upper Triassic Crisafulli and Herbst, 2011 Agathoxylon dallonii (Boureau) Crisafulli and Herbst 2 (1.3) 2–41 6–17 Argentina Upper Triassic Crisafulli and Herbst, 2011 D.(A.) dallonii (Boureau) Duperon-Laudoueneix and 1–21–2 (3) 1(1/2) 1–12 (–39) Africa Jurassic Lejal-Nicol Boureau, 1948; Duperon-Laudoueneix Jurassic– and Lejal-Nicol, 1981 Cretaceous? A. liguanensis Torres and Philippe 1–21–31 1–30 (56) Chile Lower Torres and Philippe, 2002 Jurassic A. liguanensis Torres and Philippe 1–21–3,4–6 1(1/2) 1–30 (46–56) Argentina Lower Gnaedinger et al., 2015 Jurassic A. termieri (Attims) Gnaedinger and Herbst 1–2.3 2–10 1(1/2) 2–8(–20) Africa Lower Attims, 1965 Jurassic A. termieri (Attims) Gnaedinger and Herbst 1–2.3 3–10 1(1/2) 2–6(–14) Africa Lower Giraud and Hankel, 1985 Jurassic A. termieri (Attims) Gnaedinger and Herbst 1–2.3 2–10 1(1/2) 2–14 (–20) Neuquén, Argentina Lower Gnaedinger, 2006 Jurassic A. termieri (Attims) Gnaedinger and Herbst 1–2.3 2–8,10 1(1/2) 2–12 (–20) Santa Cruz, Argentina Middle (this work) Jurassic A. wagadensis Ra, Prasad, Prakash, Singhi, Garg, Gupta, and 1–22–51 2–26 India Middle Pandey Rai et al., 2016 Jurassic A. sriperumbudurensis Kumarasamy 1 (2) 3–61 1–15 India Early Cretaceous Kumarasamy, 2016 A. protoaraucana Brea 1–23–91 2–9(–11) Argentina Middle Triassic Brea, 1997 A. protoaraucana (Brea) Gnaedinger and Herbst 1 (2) Up to 8 1(1/2) 2–12 (–19) Argentina Lower Jurassic Gnaedinger and Herbst, 2009 A. ohzuanum (Nishida, Ossawa, Nishida, and Rancusi) 1–22–41 1–11 Chile Upper Gnaedinger and Herbst Nishida et al., 1992 Cretaceous Cenozoic A. quiriaquinaense (Nishida) Gnaedinger and Herbst 1–21–51 1–10 Chile Cenozoic Nishida, 1984 A. chilensis Nishida 1–21–4.5 1 2–15 Chile Cenozoic, Nishida, 1970 Miocene

Remarks.—The comparisons made with the species of (Pant and Singh, 1987) Leiva Verón and Crisafulli in Leiva Agathoxylon described for Gondwana justify assignment of Verón et al., 2012 in most of the anatomical characters (Table 5), the La Matilde Formation specimens to a new species. In but there are differences in the radial pitting and rays. Table 5, comparisons made between species of Agathoxylon, Dadoxylon, and Araucarioxylon of Gondwana show that they share the following diagnostic characters: presence of circular, Qualitative and quantitative analysis of anatomical hexagonal, and flattened radial pitting. characters The new species is distinguished from the other Gondwanan species by the arrangement of the tracheid pits, the number of pits Tables 1 and 2 compare the four species of Agathoxylon iden- in the cross-field, and by the height of the rays (Table 5). The tified from the La Matilde Formation, Santa Cruz, Argentina. most closely comparable species is Agathoxylon semibiseriatum The anatomical characters must be taken into account for the

Figure 7. Agathoxylon santacruzense n. sp. (1) TS, detail of the tracheids and growth ring; (2–4, 6) RLS, pits on tracheid radial walls; (5, 7) RLS, detail of cross-ﬁeld pits; (8) TLS, rays. Scale bars: (1) = 190 µm; (2–7) = 45 µm; (8) = 130 µm. CTES PB 12012.

Figure 8. Agathoxylon santacruzense n. sp. (1–4) RLS, pits on tracheid radial walls; (1, 5) RLS, detail of cross-ﬁeld pits (arrow). Scale bars = 45 µm. CTES PB 12012.

Table 5. Comparison between some species of Agathoxylon/Araucarioxylon/Dadoxylon from Gondwana sharing the characters: presence of circular, ﬂattened and hexagonal, (some ﬂattened) and alternate https://www.cambridge.org/core (opposite) pits in the radial walls of the tracheids. (1/2: rays uniseriate partially biseriate; in parentheses = character with occasional condition).

RADIAL WALLS PITS RAYS CROSS ORIGIN CHARACTERS/SPECIES SERIATION DISPOSITION FIELD Width Height REFERENCE AGE A. loharense Agashe and Gowda 1–3 (4) Contiguous (separated) Alternate, opposite 1–92(1)2–27 India Permian

. Agashe and Gowda, 1978 https://doi.org/10.1017/jpa.2017.145 A.surangei Agashe, Prasad and Suresh 1–4 Contiguous (separate) Alternate 1–11 1–21–35 Agashe et al., 1981 Permian A. lathiense Agashe, Prasad and Suresh 1–4 Contiguous (separate) Alternate (opposite) in groups of 2, 3, or more 1–10 1 1–27 India Permian Agashe et al., 1981 A. bradshaawianum Bajpai and Maheshwari 1–5 Contiguous, alternate 2–4 1 (1/2) — India Permian . IPaddress: Bajpai and Maheshwari, 1986 A. bhivkundense Agashe and Prasad 1–2 Contiguous (separate) Alternate (opposite) in groups of 2, 3, or 4 1–81–21–33 India Permian Agashe and Prasad, 1989 A. parbeliense (Rao) Maheshwari 1–5 Contiguous, alternate 8–91 1–24 India Permian

177.204.168.204 Rao, 1935 A. kothariensis Agashe and Prasad 1–4 Contiguous (separate) Alternate (opposite) groups of 2–81–12 1–31–44 India Permian Agashe and Prasad, 1989 A. sp. cf. A. ningahense Maheshwari 2–3(1–4) Separate, contiguous, alternate 2–6 (10) 1 (1/2) 1–9 Antarctica Lower Maheshwari, 1972 Permian A. gondwanense (Maithy) Maheshwari 3–4(1–2.5) Contiguous, alternate or subopposite 2–8 1 (1/2) 1–43 India Lower Maithy, 1964 Permian , on Araucarioxylon semibiseriatum Pant and Singh 1–4 (5) Contiguous, separate, subopposite, alternate 4–6, 12 1 (1/2) 1–24, 38 India Permian Paleontology of Journal

03 Apr2018 at16:29:38 Pant and Sing, 1987 A. kharkhariense (Maithy) Maheshwari 1–3, groups Contiguous, alternate subopposite or opposite 2–5, 7 1 (1/2) 1–29 India Lower Maithy, 1964 Permian A. kharkhariense (Maithy) Maheshwari 1–3, groups Contiguous, alternate or opposite 3–81 2–20 Argentina Lower Crisafulli et al., 2000 Permian D. nicoli Seward 1–4 Contiguous, alternate — 1–22–17 Australia Upper Permian McLoughlin, 1992 Araucarioxylon semibiseriatum Pant and Singh 1–2 Contiguous, opposite, alternate 9 (11) 1 (1/2) 5–11 (16) Chile Upper Triassic Lutz et al., 2001

, subjectto theCambridgeCore termsofuse,available at Agathoxylon semibiseriatum (Pant and Singh) 1–2 (3) Contiguous, subopposite, alternate 6–9 1 (1/2) 1–14 Paraguay Upper Permian Leiva Verón and Crisafulli in Leiva Verón et al. Leiva Verón et al., 2012 A. matildense Zamuner and Falaschi 1 (1/2) Contiguous 4–51 1–4 Santa Cruz, Argentina Middle Jurassic Alternate Zamuner and Falaschi, 2005 D. rajmahalense Sahni (in Suryanarayana 1955) 1 (2–3) Alternate (opposite) contiguous and separate; ﬂattened — 11–12, 20 India Middle Jurassic and rarely circular, hexagonal Suryanarayana, 1956 A. pranhitaensis Rajanikanth and Sukh-Dev 1 (2) Contiguous, alternate 2–4,6 1 (1/2) 1–10 India Middle Jurassic Rajanikanth and Sukh-Dev, 1989 Agathoxylon santacruzense n. sp. 1–seriate (29%) Contiguous (100%) 2–14 (20) 1 1–16, 20 Argentina 2–seriate (63.5%) Separate (2%) (This work) Middle Jurassic 3–seriate (7.5%) Alternate (92%) Opposite (8%) D.(Araucarioxylon) rajmahalense Sahni EW: 2–3(1–3) EW: alternate, hexagonal (circular ). — 11–20 India Lower LW: 1 LW: contiguous and ﬂattened pits (circular, separate). Sahni, 1931 Cretaceous Agathoxylon sp. Ottone and Medina 1–2 Alternate 1–4 1 (1/2) 1–25 Antarctica Lower Cretaceous Ottone and Medina, 1998 A.sp.Falcon-Lang and Cantrill 1–seriate (23%) Contiguous (98%) 1–41 1–11 Antarctica Upper Cretaceous 2–seriate (76%) Separate (2%) Falcon-Lang and Cantrill, 2000 (Albian) 3–seriate (1%) Alternate (98.5%) Opposite (1.5%) A. chapmanae Poole and Cantrill 1–seriate (21%) Contiguous, alternate 2–11 1 1–25 Antarctica Upper Cretaceous 2–seriate (74%) Poole and Cantrill, 2001 3–seriate (5%) A. eocenum (Chitaley) Trivedi and Srivastava 2 (1–3) Contiguous, (separate), alternate (opposite) Groups irregular 1–7 1(1/2) 1–15 India Tertiary Chitaley, 1949; Trivedi and Srivastava, 1989 A. deccani (Shukla) Trivedi and Srivastava 1–2 Contiguous, alternate (opposite) 1–61(2)2–49 India Tertiary Shukla, 1938; Trivedi and Srivastava, 1989 Kloster and Gnaedinger—Agathoxylon wood anatomy from La Matilde Formation, Argentina 17

diagnosis of each species. Therefore, the differences between cross-field); and in TLS, ray height (in terms of number of cells these species are mainly due to the seriation and different high) was also recorded in terms of minima-maxima, occasional combinations of the tracheid radial wall pits; the type, number, maximum, and means (Table 2). and arrangement of the pits in the cross-fields and seriation; Plotted dispersion graphics based on quantitative data and height of the rays. Numerical differences between speci- for each specimen (Fig. 9) clearly reflect the differences mens of the same species, particularly in the seriation- between identified species where these species plot as single combination percentages of the radial pitting, could be continuous entities in “morphology space” (Falcon-Lang explained as intraspecific variation (Giraud and Hankel, 1985), and Cantrill, 2000, 2001). Thus, four species with an araucarian as well as the degree of preservation of the specimen or of the secondary wood structure can be distinguished by their portion in the early wood (at the beginning or at the end) where different percentages of tracheid radial pitting shapes and the data were obtained. distribution (seriation), as well as by the range and mean Anatomical characteristics of the woods were quantified in number of pits in the cross-fields (Fig. 9). Figure 9.1 shows accordance with criteria proposed by Falcon-Lang and Cantrill A. santalense and A. santacruzense n. sp. are grouped in (2000), Poole and Cantrill (2001), Gnaedinger (2012), and the same “morphology space,” that is, they have similar Gnaedinger et al. (2015). The following features were quanti- percentages of uniseriate and biseriate pits, while in the other fied: in RLS: (1) the nature of the bordered pitting on the trac- comparisons (e.g., uniseriate pits versus hexagonal shape, heid walls (a—percentages of uniseriate, biseriate, and triseriate biseriate pits versus opposite pits, and uniseriate pits versus pitted tracheids; b—percentages of circular, flattened, and cross-fields), the species clearly differ from the other taxa hexagonal-shape pitted tracheids; c—percentages of alternately (Fig. 9.2–9.4). or oppositely arranged multiseriate pits); (2) the mean, minima- Thus, A. agathioides (Kräusel and Jain) n. comb. and maxima, occasional maximum, and frequency range of pits in A. santalense (Sah and Jain) n. comb. are identified by a series the cross-fields (in terms of most common number of pits per of 1–3 pits and their combinations of flattened-hexagonal pits, with

Figure 9. Plotted dispersion graphics based on quantitative data for specimen of the La Matilde Formation. Agathoxylon agathioides A1 = CTES-PB 10659; A2 = CTES-PB 10647; A3 = CTES-PB 14236; A4 = CTES-PB 10703; A5 = CTES-PB 10702; A6 = CTES-PB 12036; Agathoxylon santalense B1 = CTES-PB 10649; B2 = CTES-PB 14239; B3 = CTES-PB 10665; Agathoxylon termieri C1 = CTES-PB 10693; C2 = CTES-PB 10696; C3 = CTES-PB 10675; C4 = CTES- PB 12043; C5 = CTES-PB 12041; Agathoxylon santacruzense D = CTES-PB 12012.

Figure 10. Plotted dispersion graphics based on Agathoxylon from La Matilde Formation and from the Gondwana. Aa = Agathoxylon africanum;Ak= A. karooensis; Ap = A. protoaraucana;Al= Agathoxylon liguaensis:Al1= Chile, Al2 = Argentina; At = A. termieri:At1= Attims, 1965; At2 = Giraud and Hankel, 1985; At3 = this work; As = Araucarioxylon sp. (Falcon-Lang and Cantrill, 2000); Ach = A. chapmanae Poole and Cantrill, 2001; Asa = A. santalense (this work); A1 = Araucarioxylon sp. 1; A2 = Araucarioxylon sp. 2 (Falcon-Lang and Cantrill, 2001); Aam = A. agathioides;Asm= A. santacruzense (this work). * = mean value.

a predominance of a series of 1–2pits,aswellasbythepresenceof (Attims) Gnaedinger and Herbst is definedbyaseriesof1–3 pits groups of pits in the first species, while in the second, biseriate and its different combinations of circular pits, with a predominance radial pitting predominates. In contrast, Agathoxylon termieri of uniseriate pits, and A. santacruzense n. sp. is well definedbya

series of 1–3 pits and its different combinations of circular, hexa- Agathoxylon is cosmopolitan, but the species A. agathioides gonal, and flattened pit shapes (Fig. 9). and A. santalense have been previously described from the In Figure 10, the dispersion graphics compare species of the Upper Jurassic–Lower Cretaceous of the Rajmahal Hills, Bihar, genus Agathoxylon using data obtained from the specimens ana- India (Sah and Jain, 1964; Kraüsel and Jain, 1964), while lyzed in this contribution (Tables 1, 2) and from the literature. For A. termieri was described from the Lower Jurassic of Africa this reason, in this study, data such as uniseriate pits, shape of the (Attims, 1965; Giraud and Hankel, 1985) and Argentina pits, and maximum number of pits in the cross-fields were col- (Gnaedinger, 2006). lected from the following Agathoxylon species: A. africanum Based on the analysis of ~250 specimens carried out so far, (Bamford) Kurzawe and Merlotti (Permo-Triassic, Jurassic– in eight localities of the Gran Bajo de San Julián sector, and Cretaceous?) and A. karooensis (Bamford) Kurzawe and Merlotti through data on the distribution of the in situ logs obtained from (Permian and Cretaceous?) from South Africa (Bamford, 2000); the census carried out in the forests, the Agathoxylon taxa A. protoaraucana (Triassic–Lower Jurassic) of Argentina described here presents a different floristic distribution in the La (Gnaedinger and Herbst, 2009); A. liguaensis Torres and Philippe Matilde Formation. Agathoxylon agathioides and A. santalense of the Lower Jurassic of Chile (Torres and Philippe, 2002) and together with Taxodioxylon Gothan and Prototaxoxylon Argentina (Gnaedinger et al., 2015); Dadoxylon (A.) termieri intertrappeum Prakash and Srivastava species are found in the (Attims, 1965; Giraud and Hankel, 1985) of the Lower Jurassic of top of the sedimentary sequence that appears in the Barda Africa; Cretaceous species described by Falcon-Lang and Cantrill Blanca and Cerro Conito localities, and in the NW Laguna La (2000, 2001); and A. chapmanae of Poole and Cantrill (2001). Guadalosa outcrop from Gran Bajo de San Julián sector and In Figure 10, the differences between fossil species are Bajo El Puma locality of the central and south-western sector clearly observed; only two groups of taxa occupy the same (Gnaedinger and Herbst, 2006; Gnaedinger, 2007b). Agathoxylon “morphology space”: (1) A. karooensis, Araucarioxylon sp. termierii associated with fern stipes and Podocarpaceae wood (Falcon-Lang and Cantrill, 2000), and the Patagonia specimens (Podocarpoxylon feruglioi Gnaedinger; Circoporopitys herbstii identified as A. santalense; and (2) A. termieri, Araucarioxylon Gnaedinger) was identified in the base of the sedimentary sp. 1 (Falcon-Lang and Cantrill, 2001), and Araucarioxylon sequence, near the carbonaceous levels in the Barda Blanca and sp. 2 (Falcon-Lang and Cantrill, 2001), when comparing Cerro Conito localities, as well as in the northern part of the characters like percentage of uniseriate pits versus maximum Estancia Meseta Chica locality (Gnaedinger, 2007b). number of cross-field pits (Fig. 10.1). When looking at anato- Finally, A. santacruzense n. sp. with Circoporoxylon mical characters, such as uniseriate pits versus the shape of the austroamericanum Gnaedinger was found only in the south- pits, the groups of species mentioned are distinguished from eastern border of Laguna del Carbón locality (Gnaedinger, each other, occupying different spaces in the above-mentioned 2007b). The distinction of the species through qualitative and graph (Fig. 10.2). quantitative analyses and according to the distribution of the The results obtained show that not only is the number of pits in specimens in the different localities and in some localities in the cross-field a diagnostic character, but also the shape of the radial different strata of the sedimentary sequence could be indicating pits (IAWA Committee, Richter et al., 2004). These parameters diverse forests at different moments during the Jurassic of the cannot only be used to discriminate genera and species of wood Patagonia (Gnaedinger, work in preparation). In this way, it found in the same Formation, but also to establish differences/ could indicate, according to the distribution of the in situ logs of similarities between other taxa described in other Formations. the fossil species found in the Barda Blanca and Cerro Conito localities, that these taxa formed small forests, or local forests, or small forests within dense forest, which is a habitat coincident Conclusions with the extant Araucariaceae.

This paper describes four coniferous wood taxa from the La Acknowledgments Matilde Formation, clearly differentiated on the basis of their qualitative and quantitative anatomical parameters, that can be This contribution was partially funded by the Secretaría General distinguished by their different percentages of tracheid radial de Ciencia y Técnica, Universidad Nacional del Nordeste pitting shapes and distribution (seriation) as well as by the range (SGCyT-UNNE.PI 2015, 2018, Q005, 2014) and the Consejo fi and mean number of pits in the cross- elds. This study con- Nacional de Investigaciones Científica y Técnicas-CONICET tributes to the method proposed by Falcon-Lang and Cantrill (PIP 2014, 2016, No. 112 201301 00317) in a grant conferred to (2000) because these parameters can be used to discriminate SCG. The authors are grateful to Katarzyna Piper, Editorial species of wood found in the same formation and between other Services (UK) for revision of the English grammar. taxa described in other formations. The findings in the La Matilde Formation of leaves and branch impressions and silicified seed and pollen cones indicate References that the “Jaramillo Petrified Forest” was mainly composed Agashe, S., and Gowda, P., 1978, Anatomical study of a gymnospermous of Coniferales belonging to the families Araucariaceae, wood from Lower Gondwana of Maharashtra: Phytomorphology, v. 28, Podocarpaceae, and? Taxodiaceae. According to the xylological p. 269–274. analysis carried out in this study, the presence of the family Agashe, S., and Prasad, K., 1989, Studies in fossil gymnospermous woods, part 7. Six new species of Lower Gondwana (Permian) gymnospermous woods from Araucariaceae in the forests of the La Matilde Formation is Chandrapur District, Maharashtra State, India: Palaeontographica, corroborated. v. 138 B, p. 71–102.

Agashe, S., Prasad, K., and Suresh, F., 1981, Two new species Araucarioxylon De Barrios, R.E., 1989, Aspectos geológicos y geoquímicos de la Formación surangei and Araucarioxylon lathiense of petrified woods from lower Chon Aike (Grupo Bahía Laura), Jurásico Medio a Superior, en el noroeste Gondwana strata: The Palaeobotanist, v. 28, p. 122–127. de la Provincia de Santa Cruz [PhD Thesis]: La Plata, Universidad Nacional Archangelsky, S., and De La Sota, R.E., 1962, Estudio anatómico de un de La Plata, 528 p. estípite petrificado de “Osmundites” de edad Jurásica, procedente del De Barrios, R.E., 1993, El Volcanismo ácido Jurásico en el Noroeste de Gran Bajo de San Julián, provincia de Santa Cruz: Ameghiniana, v. 2, Santa Cruz, Argentina: Actas 12th Congreso Geológico Argentino, v. 4, p. 153–164. p. 189–198. Attims, Y., 1965, Etude anatomique et paléogéographique de quelques De Barrios, R.E., Panza, J.L., and Nullo, F.E., 1999, Jurásico y Cretácico bois jurassiques du Maroc: Notes Du Service Geologique Du Maroc, v. 24, del Macizo del Deseado, provincia de Santa Cruz, in Caminos, R., ed., p. 33–52. Geología Argentina. Servicio Geológico Minero Argentino: Anales Baez, A.M., and Nicoli, L., 2003, Reconstruyendo la rana jurásica Instituto de Geología y Recursos Minerales, v. 29, p. 511–527. Notobratrachus degiustoi. XIX Jornadas Argentinas de Paleontología de De Giusto, J.M., 1955, Informe geológico preliminar, zona San Julián: Buenos Vertebrados: Resúmenes, p. 8. Aires, Yacimientos Petroliferos Físcales, 15 p. Bajpai, U., and Maheshwari, H., 1986, On two new fossil woods from the De Giusto, J.M., Di Persia, C.A., and Pezzi, E., 1980, Nesocratón del Deseado, Raniganj Formation with remarks on Zalesskioxylon zambesiensis from in Leanza, A.F., ed., Geología Regional Argentina: Academia Nacional de Mozambique: The Paleobotanist, v. 35, p. 39–47. Ciencias de Córdoba, v. 2, p. 1389–1430. Bajpai, U., and Singh, V., 1986, Araucarioxylon kurmarpurensis, a new Delhaes, G., 1913, Sobre la presencia del Rético en la costa patagónica: Direc- gimnospermous wood from the Upper Permian of West Bengal: The ción General de Minería y Geología, Boletín 1 Serie B, p. 5–10. Palaeobotanist, v. 35, p. 53–56. Duperon-Laudoueneix, M., and Lejal-Nicol, A., 1981, Sur deux bois homoxylés Baldoni, A., 1981, Tafofloras Jurásicas y Eocretácicas de América del Sur, in du Sud-Ouest de’l Égypte: Congrés nacional des Sociétés savantes, Volkheimer, W., and Musacchio, E.A., eds., Cuencas Sedimentarias del 106, Sect. Sciences, v. 1, p. 9–40. Jurásico y Cretácico de América del Sur: Buenos Aires, Special Publication, Echeveste, H., Fernández, R., Bellieni, G., Tessone, M., Llambías, E., 2, p. 359–391. Schlamuk, I., Piccirillo, E., and De Min, A., 2001, Relaciones entre las Baldoni, A.M., 1990, Tafofloras del Jurásico Medio de la Patagonia Extra- Formaciones Bajo Pobre y Chon Aike (Jurásico Medio a Superior) en el andina, in Volkheimer, W., ed., Bioestratigrafía de los Sistemas Regionales área Estancia El Fénix-Cerro Huemul, zona centro-occidental del Macizo del Jurásico y Cretácico de America del Sur: Comité Sudamericano del del Deseado, provincia de Santa Cruz: Revista Asociación Geológica Jurásico y Cretácico, Mendoza, v. 2, p. 313–353. Argentina, v. 56, p. 548–558. Bamford, M., 2000, Fossil woods of Karoo age deposits in South Africa and Engler, A., 1897, Die naturlichen Pflanzenfamilien. Nachtrage zum 2-4 Teil: Namibia as an aid to biostratigraphical correlation: Journal of African Earth Leipzig, Engelmann, 198 p. Sciences, v. 1, p. 119–132. Erasmus, T., 1976, On the anatomy of Dadoxylon arberi Seward, with some Bamford, M., and Philippe, M., 2001, Jurassic–Early Cretaceous Gondwanan remarks on the phylogenetical tendencies of its tracheid pits: Palaeontologia homoxylous woods: a nomenclatural revision of the genera with Africana, v. 19, p. 127–133. taxonomic notes: Review of Palaeobotany and Palynology, v. 113, Falcon-Lang, H.J., and Cantrill, D.J., 2000, Cretaceous (Late Albian) coniferales p. 287–297. of Alexander Island, Antarctica 1. Wood taxonomy: a quantitative Bertels, A., 1977, Estratigrafía y micropaleontología de la Formación San approach: Review of Palaeobotany and Palynology, v. 111, p. 1–17. Julián en su área tipo, provincia de Santa Cruz: Ameghiniana, v. 14, Falcon–Lang, H.J., and Cantrill, D.J., 2001, Gymnosperm woods from the p. 233–293. Cretaceous (mid–Aptian) Cerro Negro Formation, Byers Peninsula, Bhardwaj, D.C., 1953, Jurassic woods from the Rajmahal Hills Bihar: Palaeo- Livingston Island, Antarctica: the arborescent vegetation of a volcanic arc: botanist, v. 2, p. 59–70. Cretaceous Research, v. 22, p. 277–293. Billimoria, J.J., 1948, New species of Dadoxylon from C. P. Palaeobotany of Feruglio, E., 1949, Descripción Geológica de la Patagonia: Buenos Aires, India. VI: Journal of Indian Botanical Society, v. 26, p. 1–260. Yacimientos Petrolíferos Fiscales, v. 1, p. 334. Bose, M.N., and Maheshwari, H.K., 1974, Mesozoic conifers, in Surange, K.R., Feruglio, E., 1951, Piante del Mesozoico de la Patagonia: Publicación Instituto Lakhampal, R.N., and Bharadwaj, D.C., eds., Aspects and Appraisal of Geológico Universidad de Torino fasc. v. 1, p. 35–80. Indian Palaobotany: Lucknow, Birbal Sahni Institute of Palaeobotany, Frenguelli, J., 1933, Situación estratigráfica y edad de la “Zona con Araucarias” p. 21–223. al sur del curso inferior del río Deseado: Boletín de Informaciones Petro- Boureau, E., 1948, Etude paléoxylologique du Sahara. I. Presence du Dadoxylon leras, año 10, v. 112, p. 843–900. (Araucarioxylon) dallonii n. sp: Bulletin du Muséum d’Histoire Naturelle, Gallego, O.F., 1994, Conchostrácos Jurásicos de Santa Cruz y Chubut, v. 20, p. 420–426. Argentina: Ameghiniana, v. 31, p. 333–345. Brea, M., 1997, Una nueva especie del Género Araucarioxylon Kraus 1870, García Esteban, L., De Palacios, P., Guindeo Casasús, A., García Esteban, L., emend. Maheshwari 1972 del Triásico de Agua de la Zorra, Uspallata, Lázaro Durán, I., González Fernández, L., Rodriguez Salvador, Y., Mendoza, Argentina: Ameghiniana, v. 34, p. 485–496. Fernández García, S., Bobadilla Maldonado, I., and Camacho Atalaya, A., Calder, M.G., 1953, A coniferous petrified forest in Patagonia: Bulletin British 2002, Anatomía e identificación de maderas de coníferas a nivel de espe- Museum (Natural History): Geology, v. 2, p. 99–138. cies: Madrid, Coedición Fundación Conde del Valle de Salazar: Ediciones Chattaway, M., 1932, Proposed standard for numerical values used in Mundi–Prensa, 421 p. describing woods: Tropical Woods, v. 59, p. 20–28. García Esteban, L., Guindeo Casasús, A., Pereza Oramas, C., and de Palacios Chitaley, S., 1949, On a new species of Dadoxylon, Dadoxylon eocenum sp. de Palacios, P., 2003, La madera y su anatomía: Madrid, Coedición nov., from the District of Chhindwara, C.P., India: Journal of the Indian Fundación Conde del Valle de Salazar: Ediciones Mundi–Prensa, 327 p. Botanical Society, v. 28, p. 227–236. Giraud, B., and Hankel, O., 1985, Bois fossiles des dépôts du Karoo du Bassin Criado Roque, P., 1953, Informe preliminar reconocimiento geológico zona du Luwegu (Tanzanie méridionale): Annales de Paléontologie, v. 71, Bahia Laura, Territorio de Santa Cruz: Yacimiento Petrolíferos Fiscales p. 159–185. (inédito), p. 18. Gnaedinger, S., 2000, Leños Gimnospérmicos de la Formación La Matilde, Gran Crisafulli, A., 2001, Leños pérmicos de la Formación Yaguarí, Pérmico Superior Bajo de San Julián, provincia de Santa Cruz, Argentina: XI Simposio de Uruguay: Amenghiniana, v. 38, p. 61–72. Argentino de Paleobotánica y Palinología: Tucumán, Resúmenes, p. 38. Crisafulli, A., and Herbst, R., 2008, Maderas gimnospérmicas de la Formación Gnaedinger, S., 2006, Primer registro de maderas de la Formación Piedra Solca (Pérmico Inferior), Provincia de la Rioja, Argentina: Ameghiniana, Pintada (Jurásico Temprano), provincia de Neuquén, Argentina: Revista v. 45, p. 737–751. Museo Argentino de Ciencias Naturales, v. 8, p. 171–177. Crisafulli, A., and Herbst, R., 2011, La Flora Triásica del Grupo El Tranquilo, Gnaedinger, S., 2007a, Planoxylon Stopes, Protelicoxylon Philippe y Herbstiloxylon provincia de Santa Cruz (Patagonia): Leños Fósiles: Ameghiniana, v. 4, n. gen. (Coniferales) de la Formación La Matilde (Jurásico Medio), Provincia de p. 275–288. Santa Cruz, Argentina: Ameghiniana, v. 44, p. 321–335. Crisafulli, A., and Lutz, A., 1997, Leños gimnospérmicos de la Formación Gnaedinger, S., 2007b, Podocarpaceae woods (Coniferales) from middle Melo (Pérmico Inferior), Uruguay. Parte 1: Barakaroxylon Surange Jurassic La Matilde Formation, Santa Cruz province, Argentina: Review of y Maihty, 1962 y Araucarioxylon Kraus, 1870: Ameghiniana, v. 34, Palaeobotany and Palynology, v. 147, p. 77–93. p. 437–445. Gnaedinger, S., 2012, Ginkgoaleans woods from Middle Jurassic of the Crisafulli, A., Lutz, A., and Melchor, R., 2000, Maderas gimnospérmicas de la Argentina. Taxonomic considerations and palaeobiogeographical distribu- Formación Carapacha (Pérmico), provincia de La Pampa, Argentina: tion: Geobios, v. 45, p. 187–198. Ameghiniana, v. 37, p. 181–191. Gnaedinger, S., and Herbst, R., 2006, El género Prototaxoxylon Krausel y Crisafulli, A., Herbst, R., and Manza Stortti, L., 2009, Maderas gimnospérmicas Dolianiti (Taxales) de la Formación La Matilde (Jurássico Médio), de la Formación Tres Islas (Pérmico Inferior) de Uruguay: Gaea, v. 5, Gran Bajo de San Julián, Santa Cruz, Argentina: Amenghiniana, v. 43, p. 1–14. p. 123–138.

Gnaedinger, S., and Herbst, R., 2009, Primer registro de maderas gimnos- Morton, S., and Herbst, R., 2001, Nuevas especies del género Diplodon Spix pérmicas de La Formación Roca Blanca (Jurásico Inferior), provincia de (Bivalvia, Unionidea) del Jurásico Medio (Formación La Matilde), Santa Cruz, Argentina: Ameghiniana, v. 4, p. 59–71. Provincia de Santa Cruz, Argentina: Revista Museo Argentino Ciencias Gnaedinger, S., García Massini, J.L., Bechis, F., and Zavattieri, A.M., 2015, Naturales, v. 3, p. 159–164. Coniferous woods and wood-decaying fungi from the El Freno Formation Nishida, M., 1970, On some fossil plants from Chile, South. America: (Lower Jurassic), Neuquén Basin, Mendoza Province, Argentina: Annual Report of the Foreign Students’ College of Chiba University, v. 5, Ameghiniana. v. 52, p. 447–467. p. 13–18. Greguss, P., 1955, Identification of Living Gymnosperms on the Basis of Nishida, M., 1984, The anatomy and affinities of the petrified plants from the Xylotomy: Budapest, Akadémiai Kiado, 508 p. Cenozoic of Chile. IV. Dicotyledonous woods from Quiriquina island, near Hartig, T., 1848, Beitrage zur Geschichte der Pflanzen un zur Kenntniss der Concepción, in M. Nishida, M., ed., Contributions to the Botany in the Norddeutschen Braunko Flora: Botanische Zeitung, v. 6, p. 185–190. Andes I: Tokyo, Academia Scientific Book Inc, p. 111–121. Henkel, A., and Hochstetter, W., 1865, Synopsis der Nadelhölzer deren Nishida, M., Ohsawa, T., Nishida, H., and Rancusi, H. M., 1992, Permineralized charakteristischen Merkmale nebst Andeutungen über ihre Cultur und coniferous woods from the XI Region of Chile, Central Patagonia: Research Ausdauer in Deutschlands Klima: Stuttgart, J. G. Cottaschen Buchhandlung, Institute of Evolutionary Biology, Science Report, v. 7, p. 47–59. 446 p. Ottone, E.G., and Medina, F.A., 1998, A wood from the Early Cretaceous of Herbst, R., 1977, Dos nuevas sp. de Osmundacaulis (Osmundaceae, Filices) James Ross Island, Antarctica: Ameghiniana, v. 35, p. 291–298. y otros restos de Osmundales de Argentina: Corrientes, Facena, v. 1, Pant, D.D., and Singh, V.K., 1987, Xylotomy of some woods from Raniganj p. 19–40. Formation (Permian), Raniganj Coalfield, India: Palaeontographica, v. 203 B, Herbst, R., 2003, Osmundacaulis tehuelchense n. sp. (Osmundaceae, Filices) p. 1–82. from the Middle Jurassic of Santa Cruz province (Patagonia, Argentina): Panza, J.L., 1982, Descripción geológica de las Hojas 53e “Gobernador Courier Senckenberg Forschungs institute, v. 241, p. 85–95. Moyano” y 54e “Cerro Vanguardia”: Servicio Geológico Nacional Herbst, R., and Salazar, E., 1999, Revisión de la flora Matildense del Gran (inédito), 197 p. Bajo de San Julián, Provincia de Santa Cruz, Argentina: Facena. v. 14, Panza, J.L., 1984, Descripción geológica de las Hojas 54f “Bajo de la Leona” y p. 7–24. 54g “Bahia Laura”, pcia, de Santa Cruz: Servicio Geológico Nacional Herbst, R., Lutz, A., Gallego, O., and Acevedo, E., 1995, El bosque petrificado (inédito), 170 p. del Gran Bajo de San Julián, provincia de Santa Cruz (Resúmen): Panza, J.L., 1986, Descripción geológica de la Hoja 54d “La Manchuria”, Pro- Ameghiniana, v. 32, p. 107. vincia de Santa Cruz: Buenos Aires, Servicio Geológico Nacional (inédito), Holden, R., 1917, On the anatomy of two Palaeozoic stems from India: Annals 141 p. of Botany, v. 31, p. 315–326. Panza, J.L., 1995, Hoja Geológica 4966-I-II Bahía Laura, escala 1:250.000, Jeyasingh, D.E.P., and Kumarasamy, D., 1995, An unusual pycnoxylic wood Provincia de Santa Cruz: Dirección Nacional del Servicio Geológico, from a new upper Gondwana locality in Tamil Nadu, India: Review of Boletín, v. 214, p. 1–84. Palaeobotany and Palynology, v. 85, p. 341–350. Panza, J.L., 1998, Hoja Geológica 4769-IV Monumento Nacional Bosques Jones, T.P., and Rowe, N.P., 1999, eds, Fossil Plants and Spores: Modern Petrificados, escala 1:250.000: Santa Cruz, Servicio Geológico Minero Techniques: Special Publication of the Geological Society of London, Argentino, Boletín, 257 (unedited). 396 p. Panza, J.L., and Cobos, J.C., 1998, Hoja geológica 4769-III Destacamento La Kräusel, R., 1962, Appendix on Antartic fossil wood, in Plumstead, E.P., ed., Marí, escala 1:250.000: Santa Cruz, Servicio Geológico Minero Argentino Fossil Floras of Antartica: Trans-Antarctic Expedition, Scientific Reports 9, (inédito). p. 133–140. Panza, J.L., and De Barrios, R., 1989, Descripción geológica de las Hojas 56f Kräusel, R., and Dolianiti, E., 1958, Gymnospermenhölzer aus dem Paläozoi- “Cordón Alto” y 56g “Puerto San Julián”, Provincia de Santa Cruz: Servicio kum Brasiliens: Palaeontographica, v. 104 B, p. 115–137. Geológico Nacional, (inédito), 155 p. Kräusel, R., and Jain, K., 1964, New coniferous wood from the Rajmahal Hills, Panza, J.L., and Irigoyen, M.V., 1995, Hoja Geológica 4969-IV Puerto San Bihar, India: The Palaeobotanist, v. 12, p. 59–67. Julián, escala 1:250.000, Provincia de Santa Cruz: Dirección Nacional Kumarasamy, D., 2016, A new fossil conifer wood from the Sriperumbudur Servicio Geológico, Boletín, v. 211, p. 1–78. Formation, Tamil Nadu, India: International Journal of Geology and Earth Panza, J.L., and Marín, G., 1996, Hoja Geológica 4969-1 Gobernador Gregores, Science, v. 2, issue 3, p. 28–32. escala 1:250.000, Provincia de Santa Cruz: Dirección Nacional del Servicio Lakhanpal, R.N., Prakash, U., and Bande, M.B., 1977, An Araucarian fossil Geológico, Boletín, v. 239, p. 1–104. wood from the Deccan Intertrappean beds of Mohgaon Kalan: The Philippe, M., and Bamford, M.K., 2008, A key to morphogenera used for Palaeobotanist, v. 24, p. 125–131. Mesozoic conifer-like woods: Review of Palaeobotany and Palynology, Leiva Verón, V., Crisafulli, A., Herbst, R., Filippi, V., and Molina, S., 2012, v. 148, p. 184–207. Guavirá, una nueva localidad con maderas fósiles de la Formación Tacuary Poole, I., and Cantrill, D., 2001, Fossil woods from Williams Point Beds, (Pérmico Superior) de Paraguay: Gaea—Journal of Geoscience, v. 8, n. 2, Livingston Island, Antarctica: a Late Cretaceous southern high latitude p. 67–81. flora: Palaeontology, v. 44, p. 1081–1112. Lucas, R.C., and Lacey, W.S., 1981, A permineralized wood flora of probable Pujana, R.R., Marenssib, S.A., and Santillana, S.N., 2015, Fossil woods from the Cenozoic age from King George Island, South Shetland Island: British Cross Valley Formation (Paleocene of Western Antarctica): Araucariaceae- Antarctic Survey Bulletin, v. 53, p. 147–151. dominated forests: Review of Palaeobotany and Palynology, v. 222, Lutz, A., Cisafulli., A., and Herbst, R., 2001, Contribución al estudio p. 56–66. xiloflorístico de la Formación La Ternera, Triásico Superior (Chile): Rai, J., Prasad, M., Prakash, N., Singh, A., Garg, S., Gupta, M., and Pandey, D.K., Ameghiniana, v. 38, p. 119–127. 2016, Gymnosperm fossil woods from Gangta Bet, eastern Kachchh, Maheshwari, H.K., 1964, Studies in Glossopteris flora of India—16 Dadoxylon western India: Journal of Palaeontological Society of India, v. 61, p. 111–122. jamudhiense—a new species of fossil wood from the Raniganj stage of Rajanikanth, A., and Sukh-Dev, A., 1989, The Kota Formation: fossil flora and Jharia coalfield, Bihm: Palaeobotanist, v. 12, p. 267–269. stratigraphy: Geophytology, v. 19, p. 52–64. Maheshwari, H.K., 1972, Permian wood from Antarctica and revision of some Rao, H.S., 1935, On a sphaerosiderite, containing a new species of Dadoxylon Lower Gondwana wood taxa: Palaeontographica, v. 203 B, p. 1–82. (D. parbeliense) from the Lower Gondwana Coal Measures of India: Maithy, P., 1964, Two new species of Dadoxylon from the Lower Gondwana of Records of the Geological Survey of India, v. 69, p. 174–183. India: Studies in the Glossopteris flora of India: The Paleobotanist, v. 13, Richter, H.G., Grosser, D., Heinz, I., and Gasson, P.E., 2004, eds, International p. 89–93. Association of Wood Anatomists list of microscopic features for softwood Maniero, J., 1946, Uma nova madeira fóssil do Brasil Meridional, Dadoxylon identification: IAWA Journal, v. 25, p. 1–70. roxoi sp. n: Revista do Instituto Adolfo Lutz, v. 6, p. 65–76. Roberts, D. L., Bamford, M., and Millsteed, B., 1997, Permo-Triassic macro- Marguerier, J., 1976, Paleoxylologie du Karoo Malgache. Étude d’un bois fos- plant fossils in the Fort Grey silcrete, East London: South African Journal of sile de la sakamena (District de Mahabo) Dadoxylon (Araucarioxylon) Geology, v. 100, p. 157–168. malaimbandense n. sp: Actes du 97ème Congrés National des Societés Rößler, R., Philippe, M., Van Konijnenburg-Van Cittert, J., Mcloughlin, S., Savantes (Nantes), p. 87–105. Sakala, J., and Zijlstra, G., coordinating authors (and 35 additional authors) Mazzoni, M.M., Spalletti, L.A., Iñiguez Rodriguez, A.M., and Teruggi, M., 2014, Which name(s) should be used for Araucaria-like fossil wood?— 1981, El Grupo Bahía Laura en el Gran Bajo de San Julián, Provincia Results of a poll: Taxon, v. 63, p. 177–184. de Santa Cruz: 8th Congreso Geológico Argentino, Actas, v. 3, p. 485–507. Sah, S.C.D., and Jain, K.P., 1964, Some fossil woods from the Jurassic of McLoughlin, S., 1992, Late Permian megafossils from the Bowen Basin, Rajmahal Hills, Bihar, India: The Palaeobotanist, v. 12, p. 169–180. Queensland, Australia: Part 1: Palaeontographica, v. 228 B, p. 105–149. Shukla, V.B., 1938, On a new species of Dadoxylon, D. deccani sp. n. from Menéndez, C., 1960, Cono masculino de una conífera fósil del Bosque the Deccan Intertrappean series: Journal Indian Botanical Society, v. 18, Petrificado de Santa Cruz: Ameghiniana, v. 2, p. 11–20. p. 35–67.

Shukla, V. B., 1944, On a new species of Dadoxylon D. resinosum, sp. n. from paleoxilológicos en el Jurásico de América del Sur: Revista Geológica de the Chhindwara District of C.P: Journal Indian Botanical Society, v. 23, Chile, v. 29, p. 151–165. p. 83–90. Torres, T., and Rallo, V., 1981, Anatomía de troncos fósiles del Cretácico Singer, P., and Archangelsky, S., 1957, Un nuevo hongo fósil de los bosques superior de Pichasca, en el Norte de Chile: Anais II Congreso Latinoamer- petrificados de Santa Cruz. Patagonia: Ameghiniana, v. 1, p. 40–41. icano Paleontologia, Porto Alegre, Brasil, v. 1, p. 385–397. Singhai, L.C., 1958, On a new species of Dadoxylon, D. shuklai sp. n. from Trivedi, B.S., and Srivastava, R., 1989, Gymnospermous woods from Early Deccan Intertrappean beds of Chhindwara district, Madhya Pradesh: Tertiary of Chhindwara District, Madhya Pradesh: Phytomorphology, v. 3, Journal Paleontological Society Indian, v. 3, p. 136–141. p. 61–68. Spalletti, L., Iñiguez Rodriguez, M., and Mazzoni, M., 1982, Edades radiométricas Vagyani, B.A., and Raju, A.V.V., 1981, A new species of fossil gymnospermous de piroclastitas y volcanitas del Grupo Bahia Laura, Gran Bajo de San Julián, wood Araucarioxylon Kraus from Nandori, Mahashtra State: Biovigyanam, Santa Cruz: Asociación Geológica Argentina, v. 37, p. 483–485. v. 7, p. 11–13. Spegazzini, C., 1924, Coniferales fósiles patagónicas: Anales Sociedad Vogellehner, D., 1965, Untersuchungen zur Anatomie und Systematik der Científica Argentina, v. 98, p. 125–139. verkieeselten Hölzer aus dem fränkischen und süd-thüringischen Keuper: Stipanicic, P.N., and Reig, O.A., 1957, El “Complejo Porfírico de la Erlanger Geologische Abhandlungen, v. 59, p. 1–76. Patagonia Extrandina” y su fauna de anuros: Acta Geologica Lilloana, v. 1, Vozenin-Serra, C., and Salard-Cheboldaeff, M., 1992, Les bois Mineralises p. 185–230. Permo-Triasiques de Nouvelle Caledonie. Implications Phylogenetique et Stockey, R.A., 1977, Reproductive biology of the Cerro Cuadrado (Jurassic) Paleogeographique: Palaeontographica, v. 225 B, p. 1–25. fossil conifers: Pararaucaria patagonica: American Journal Botany, v. 64, White, D., 1908, Flora fóssil das Coal Measures do Brasil: Relatório Final da p. 733–744. Comissão dos Estudos das Minas de Carvão de Pedra do Brasil, Rio de Stockey, R.A., 1978, Reproductive biology of Cerro Cuadrado fossil conifers: Janeiro, v. l, p. 337–617. ontogeny and reproductive strategies in Araucaria mirabilis (Spegazzini) Yadav, R.R., and Bhattacharyya, A, 1996, Climatic significance of growth rings Windhausen: Palaeontographica, v. 166 B, p. 1–15. in the Mesozoic woods from India: Palaeobotanist, v. 45, p. 57–63. Stockey, R.A., and Taylor, T.N., 1978, On the structure and evolutionary rela- Zamuner, A., and Falaschi, P., 2005, Aghatoxylon matildense n. sp., leño arau- tionships of the Cerro Cuadrado fossil conifer seedlings: Botanical Journal cariáceo del Bosque petrificado del cerro Madre e Hija, Formación of the Linnean Society, v. 76, p. 161–176. La Matilde (Jurásico medio), provincia de Santa Cruz, Argentina: Suryanarayna, K., 1956, Dadoxylon rajmahalense Sahni from the coastal Ameghiniana, v. 42, p. 339–346. Gondwanas of India: Paleobotanist, v. 4, p. 89–90. Zamuner, A.B., 1996, Araucarioxylon petriellae n. sp. una posible Glossopter- Tidwell, W.D., and Medlyn, D.A., 1993, Conifer wood from the Upper Jurassic idal de la Formación Melo (Pérmico inferior) Uruguay: Amenghiniana, of Utah, USA. Part II: Araucarioxylon hoodii sp. n: The Palaeobotanist, v. 33, p. 77–82. v. 42, p. 70–77. Torres, T., and Philippe, M., 2002, Nuevas espécies de Agathoxylon y Baieroxylon del Liásico de La Ligua, Chile, y evaluación de antecedentes Accepted 26 November 2017